Natural Resources, std-09

Natural Resources
:- The living and non-living components of nature which are used by humans to meet their requirements are called natural resources.

E.g. Soil, water, air, etc. 

⭐ Biosphere

:- The Life supporting zone of earth where the atmosphere, hydrosphere and lithosphere interact and make life possible is called biosphere.

:- There are mainly three zones of biosphere, namely

                             1. Lithosphere

                             2. Hydrosphere

                             3. Atmosphere

1. Lithosphere

:- The outer crust of the earth is called lithosphere.

:- It represents the land part of the earth.

2. Hydrosphere

:- The zone in which water exist is called  hydrosphere.

:- It is also found as underground water resources.

:- Water covers about 75% of the earth's surface.

3. Atmosphere

:- The zone of earth where air cover the earth like a blanket is called atmosphere.

:- It is divided into five zones or layers:

a. Troposphere(0-20 km)

b. Stratosphere (20-50 km)

c. Mesosphere(50-70km)

d. Thermosphere(70-100km)

e. Exosphere (100-300km)
                            👇👇

Components of Biosphere

:- There are mainly two components of  

    biosphere. 

1. Biotic Components

  :- Living part of the biosphere are called 

     biotic components. 

E.g. Plants, Animal, microbes, etc. 

2. Abiotic Components

:- Non-living part of the biosphere are 

   called abiotic components. 

E.g. Air, water, air, soil, temp, etc. 

Types of Natural Resources

:- There are mainly two types of natural 

   resources:

 1. Inexhaustible Natural Resources

:- The natural resources which occur in such abundance that they are not likely to get exhausted despite continuous use are called inexhaustible natural resources. 

E.g. Air, water, solar energy, etc. 

2. Exhaustible Natural Resources

:- The natural resources which occur in limited quantity are called exhaustible natural resources. 

:- It is of two types:

  a. Renewable Resources

:- The exhaustible resources which get replenished regularly are called renewable resources. 

:- It include both living and non living resources. 

E.g. Forests, wildlife, soil and underground water, etc. 

b. Non-renewable resources

:- The exhustible resoures which can not be replenished in nature are called non renewable resoures. 

:- Coal, Petroleum, Mineral, etc. 

🌟Air- The breathe of life

:- It is essential for the survival of all living organisms. 

:- It is mixture of gases like Nitrogen, Oxygen, Other gases ( CO2, NH3, Argon, Water vapour, Ozone, Helium, etc)

:- Constituenty of these👆 gases in atmosphere 👇

-Nitrogen- 78.09%

-Oxygen- 20.95%

-CO2- 0.4% ,rest of other gases. 

Importance of air

i. Air is necessary for controlling atmospheric temperature. 

ii. Oxygen is supporter of combustion.

iii. Nitrogen in air is necessary for manufacturing proteins by plants.

iv. Carbon dioxide is utilised by plants for photosynthesis and in fire extinguisher.

:- Atmosphere plays a key role in climate control. 

:- The movement of air is called wind or fast blowing air is called wind.

Question 1.  

 How wind is caused?

Ans:- Wind is caused by differences in atmospheric pressure between two or more places.

Question 2. 

What is the direction of wind during day and night?

Ans:- During day - The direction of the wind is from sea to the land Whereas

During night - The direction of the wind is from land to sea. 

Question 3. 

 How does air move in diverse directions?

Ans:- The movement of air in diverse directions is caused due to the uneven heating of the atmosphere in different regions of the earth, the rotation of the Earth, and the presence of mountain ranges in the paths of the wind which distract the easy flow of air.

Question 4. 

How does it rain?

Ans:- The formation of rain can be explained in the following way:

⭐. During daytime due to energy of sun, water bodies are heated and a large amount of water evaporates and goes into the air.

⭐. Some of this water vapour also get into the atmosphere because of various biological activities.

⭐. At the same time air also gets heated which rises up and carries the water vapour with it.

⭐. As the air rises up, it expands and cools down. This cooling results into the condensation of water vapour in the air to form tiny droplets 💧.

⭐. This condensation of water is facilitated by some particles of dust that act as the nucleus for these drops to form around.

⭐. The Water droplets condense

further and grow bigger in size. The droplets grow so big and heavy that they can no longer float in the air and fall down in the form of rain. 

⭐. Sometimes, when the temperature of air is very low, water may precipitate in the form of snow, sleet or hail. 

Pollution

:- An undesirable change in the physical, chemical and biological characteristics of our surroundings that harms human life and other living beings is called pollution. 

Pollutants

:- The substances that cause pollution are called pollutants.

:- There are mainly two types of pollutants:

 1. Gaseous Pollutants ( e.g. Sulphur dioxide, Nitrogen oxides, Carbon monoxide & dioxide, chlorine, methane, Hydrogen cyanide and ammonia, etc. 

2 Particulate Pollutants or SPM ( e.g. Smokes or Smog, fly ash and dust, etc. )

⭐ Types of Pollution

:- There are mainly four types of pollution:

 a. Air pollution

 b. Water pollution

 c. Land/Soil pollution

 d. Noise pollution

Air Pollution

:- The occurrence or addition of foreign particles, gases and other materials into the air, which adversely affect the health, vegetation and property is called air pollution.

🙁Types of air pollution

:- There are mainly two types of air pollution:

a. Natural Air pollution ( e.g. forest fire, dust storm, etc.)

b. Man made Air pollution ( e.g. burning of fossil fuels, vehicles, stone crushing, etc. )

🌟. Effects of air pollution

1. Carbon monoxide combines with the hemoglobin molecules in human blood and causes suffocation. 

2. Nitric oxide(NO) in high concentration causes respiratory problems, internal bleeding, oxygen deficiency, pneumonia and lung cancer.

3. Air pollutants like suspended particulate matter cause asthma, lung cancer. 

4. Air Pollution reduces soil moisture and thus, agriculture crops are damaged resulting in heavy economic losses to farmers.

😯Prevention and control of air pollution

:- Air pollution can be prevented or controlled in many ways:

1. By using better designed equipments and smokeless fuels in industries and at home.

2. By moving pollution causing industries to remote areas.

3. By using of precipitators, scrubbers and filters to control ejection of particulate matter produced by industries.

4. By using environment friendly fuels, such as CNG in automobiles instead of petrol or diesel.

5. By planting more and more trees surrounding industrial establishments, along the roadside to reduce carbon dioxide level in the environment.

6. By generating awareness in public through films, lectures, street plays and debates about the harmful effects of air pollution. 

Note:- Lichen is considered as the natural indicator of air pollution. 

🌟Water: A Wonder Liquid

:- Water is precious for all living organisms because most of the biological activities carried out by water. 

:- 75% of earth surface is covered by water.

Sources of Water

:- Rain, river, ponds, lakes, seas, oceans, etc.

⭐Water pollution

:- A change in physical, chemical and biological properties of water by the addition of undesirable substances is called water pollution.

:- It may have harmful effects on human and aquatic life. 

:- Agents or substances that pollute water are called water pollutants. 

:- There are mainly three types of water pollutants:

1. Physical water pollutants

:- It includes - heat(temp), oil spills. 

2. Chemical water pollutants

:- It includes - organic wastes, detergents, fertilizers, pesticides (DDT, DDE, BHC, etc.)

 and radioactive wastes. 

3. Biological water pollutants

:- It includes - pathogens such as viruses, bacteria, protozoa, fungi, Helminthes, nematodes, etc. 

Sources or Causes of Water pollution

:- Flowchart to understand causes of water pollution 👇

                                   OR

⭐ Harmful Effects of Water Pollution

1. Human diseases such as typhoid, cholera, dysentery, jaundice, and hepatitis. 

2. Disturbance in ecological balance

3. Removal of desirable substances from water bodies such as Oxygen. 

[ BOD or Biological oxygen demand- It indicates the quality of waste water. 

It also refers to the amount of dissolved oxygen needed by bacteria or aquatic life. ]

4. Effects of thermal pollution or change in temperature-  It affects breeding of aquatic animals. The eggs and larvae of various animals are particularly susceptible to temperaturechanges.etc.  

🌟 Prevention and control of Water Pollution

:- Water Pollution can be prevented and controlled in many ways:

1. By setting up sewage water treatment plants.

2. By using of septic tanks in houses to avoid direct outlet of faecal matter and other wastes. 

3. By avoiding contamination of rivers, lakes and ponds by washing clothes, bathing, etc.

4. Not throwing waste food materials, paper, biodegradable vegetables and plastics into open drains.

5. By treating industrial effluents before discharging into rivers, separate channels for river and sewage water.

6. By generating public awareness about the maintenance of ponds, river, lakes and Wells in rural and urban areas. 

🌟Soil

:- It is one of the important resource which influence and decide the diversity of life in an area. 

:- Soil is formed by the weathering of rock. 

:- Formation of soil is very slow process. 

:- Soil contains  mainly following things

   a. Small particles of rock,

   b. Decayed living organisms on the 

       surface called humus and 

   c. Various forms of microscopic life. 

Soil Pollution

:- The removal of useful components from the soil and addition of harmful substances which adversely affect the fertility of soil is called soil Pollution. 

:- It is caused by solid wastes and 

   chemicals. 

Soil Erosion

:- The removal of the top layer of soil from it's original position to another place by the action of strong wind and rain water is called soil erosion. 

⭐Causes of soil Erosion

1. Strong winds. 

2. Heavy rains. 

3. Improper farming. 

4. Human actions such as deforestation, 

    overgrazing by domestic animals. 

5. Dust storm. 

6. Frequent flood. 

⭐Effects of Soil Erosion

a. Loss of fertility and desertification. 

b. Landslides in hilly areas. 

c. Famines( excessive shortage of food ).

d. Silting of water reservoir. 

🌟 Prevention of Soil Erosion

a. Intensive cropping( fields remain covered with crops throughout the year).

b. Sowing grasses and Afforestation. 

c. Terrace farming. 

d. Making strong embankments along the 

    river banks. 

🌟 BIOGEOCHEMICAL CYCLES

:- The circulation of matter or nutrient elements like carbon, hydrogen, oxygen, nitrogen, water, and energy between biotic world and abiotic world is called the biogeochemical cycle. 

🌞Characteristics of Biogeochemical cycles

1. It helps in recycling of important materials in the nature. 

2. It operates through air, water, soil and living world. 

3. It helps in maintaining the nutrient pool of the earth. 

🌟Water Cycle

:- It is also known as hydrological cycle. 

:- The circulation of water within the earth's hydrosphere which involves continuous exchange of water between atmosphere, land surface and groundwater and living beings is called water cycle.

The water cycle involves following main steps. 

1. Evaporation

:- It is the transfer of water from the surface of water bodies into the atmosphere. 

2. Condensation

:- These water vapours on evaporation condense and form clouds. 

3. Precipitation

:- The water vapours that condense to form clouds precipitate to form rain and snow. 

:- When clouds are cooled due to rising up, the small droplets 💧 in them become still cooler and they come closer to each other.

:- Many droplets combine to form big drops of water. 

:- These drops are so big that they can no longer float in air and fall down on earth as rain. 

4. Infiltration

:- All the rain water falling on the surface does not floats to the sea. Some of it seeps into soil and become part of the underground reservoir of fresh water. 

In this way water recycle in nature.

🌟 Nitrogen Cycle

:- About 78% of nitrogen present in earth's atmosphere. 

:- It is an essential component of life because it takes part in the Formation of proteins, vitamins and nucleic acid(DNA & RNA ). 

:- The cyclic process by which nitrogen element is circulated continuously through the living and non-living components of the biosphere is called the nitrogen cycle.

*Nitrogen Cycle has the following 5 steps:

🔷 Nitrogen fixation

🔷 Nitrogen assimilation

🔷 Ammonification

🔷 Nitrification

🔷 Denitrification

⭐ Nitrogen Fixation

:-  The process of converting free nitrogen of the atmosphere into the nitrogen compounds is called nitrogen fixation.

:- It takes place in two ways:

🔹 Atmospheric Nitrogen fixation

:- During lightning in the sky, when high temperature and pressure is created in the air, the Nitrogen gas present in the atmosphere reacts with oxygen to produce oxides of Nitrogen.

:- These oxides of Nitrogen get dissolved in rainwater forming dilute nitric and nitrous acids come and fall on the land along with rain water.

:- These nitric and nitrous acid react with the alkalis  of the soil( like limestone ) to turn into nitrates, which is used by various life forms.

N2 + O2 -----> 2NO

2NO + O2 ------> 2NO2

4NO2 + 2H2O + O2 ----> 4HNO3

CaCO3+2HNO3--->Ca( NO3 )2 + H2O+ CO2

🔹 Biological Nitrogen fixation

:- Atmospheric Nitrogen fixed by 

1. Azotobacter

2. Clostridium &

3. Rhizobium (They live in the root nodules of dicot leguminous plants and can fix atmospheric Nitrogen into nitrates). 

Note:- certain blue green algae like Anabaena and Nostoc and non leguminous plants like Ginkgo can also fix atmospheric nitrogen into nitrates. 

⭐ Nitrogen assimilation

:- The process of conversion of inorganic Nitrogen compounds into organic that become a part of living organisms is called nitrogen assimilation. 

⭐ Ammonification

:- The process of conversion of complex organic compounds like proteins into ammonia is called ammonification.

⭐ Nitrification

:- The process of conversion of ammonia into nitrites and nitrates is called nitrification. 

⭐ Denitrification

:- The conversion of nitrte and nitrite salts to elemental nitrogen is called denitrification. 

:- It is carried out in the soil by free - living bacteria called Pseudomonas. 

                               👇👇

        
                                   OR

🌞Carbon Cycle 

:- The cyclic process in which carbon is circulated continuously through the living and non-living components of the biosphere is called carbon cycle. 

:- Carbon is a basic constituent of all life forms.
:- 0.4% (was 0.03%) CO2 present in atmosphere. 

:- The steps of carbon cycle in nature are as follows:

🔹Carbon is present as CO2 gas in the atmosphere. 

:- Green plants use this CO2 to prepare their food by the process of photosynthesis. 

🔹When animals eat the plant, plant carbohydrate is converted into animal carbohydrate.

🔹The process of combustion also adds carbon dioxide in the atmosphere.

🔹CO2 is also present in the dissolved state in water. This gets converted into calcium carbonate in limestone and other carbonate rocks. 

🔹 When acid rain falls on these rocks, then CO2  gas is released. 

🔹Volcanic eruption and hot springs also add CO2 in the atmosphere. 

:- Thus, there is a continuous exchange of carbon dioxide between atmosphere, water bodies and living beings through physical and biological activities.
:- Flow chart to represent the Carbon Cycle.                                     👇👇

                                   OR

Oxygen is returned to the atmosphere in only one major process coma that is, photosynthesis.

     
🌞 Oxygen Cycle

:- The cycle that maintains the levels of oxygen in the atmosphere is called oxygen cycle. 

:- 20.95% (was 21%) oxygen present in atmosphere. 

:- It is a very abundant element on our earth & found in the elemental form as well as in combined form. 

:- It is an essential component of most biological molecules like carbohydrates, proteins, nucleic acids and fats or lipids.

--> oxygen is used of in the atmosphere by three processes:

1. Combustion.                                       

2. Respiration. 

3. In the Formation of Oxides of Nitrogen. 

:- oxygen is returned to the atmosphere only one major process, that is, photosynthesis. 

:- flowchart 👇👇

  

🌞 Ozone layer
:- It is a thick layer of ozone gas.
:- located in stratosphere.
:- It protects us from UV radiations of sun/sunlight.

:- At ground level ozone is                 poisonous/harmful pollutant which damages plants and building materials and hazardous to human health.     

🔷 Ozone Hole 
:-  The depletion of ozone layer causes             ozone hole.
Note :- In 1993 about 70% of the Antarctic region Ozone was destroyed over an area about the size of North America. 
 :- Picture of Ozone hole Over Antarctica
                                  👇👇

* Causes
:- Ozone layer depletion takes place due to usage of ODS i.e Ozone depleting substances like -
:- CFCs(chlorofluorocarbons), aerosols, Methane or CH4, Nitrous Oxides, Chlorine and Bromine containing compounds such as - 👇
   Methyl Chloroform, Carbon tetrachloride,
Halon ( industrial chemicals ) & Soil fumigants.
*Formation of Ozone Molecule
i. O2 --------> O +  O ( ozone atoms )
 :- Oxygen molecule breaks into free oxygen/ozone atoms by the action of UV radiation from Sun. 
ii.  O2  +  O -------> O3 ( ozone molecule)
:- Free oxygen atom react or fuse with any molecular form of oxygen and form ozone molecule which further form ozone layer.
*Effects
:- Effects of depletion of ozone layer are as follows 👇
i. It cause diseases in humans such as Cataract, Skin cancer, dimming of eyesight, malfunctioning of Immune system.
ii. It causes mutation.
iii. It affect terrestrial and aquatic food chains.
iv. It also causes global warming.
Prevention
:- International agreement to prevent depletion of ozone layer is -👇
I. Kyoto Protocol
  :- It was held in Kyoto in 1997.
Aim:- To reduce emission of green house gases at the level of 5% below the 1986/1990 level by 2008 - 2012 AD.
:- Two more conventions were also held for the same purpose such as 👇
  i. Earth Summit - 1992  &
 ii. Monotreal Protocol - 1987 .
:- These all international agreements are under UNEP i.e United Nations Environment Programme.
😕Greenhouse Effect 

:- An increase in the percentage of greenhouse gases which prevent the escape of heat from earth would increase the average temperature on earth worldwide is called greenhouse effect. 

:- Greenhouse gases - CO2, CFCs ( chlorofluoro carbons), CH4, Water vapour, N2O5( Nitrous oxides). 

🤨Global Warming

:-  An increase in earth's temperature due to increase in the concentration of greenhouse gases is called global warming. 

➤ Causes

a. Carbon dioxide 

 :- Human activities like burning of fossil        fuels etc.
b. Methane - CH4
:- Marshes, Paddy field, cattle shed etc.
c. Chlorofluoro carbons - CFCs
:- Refrigerators, A.C, Aerosol etc.
d. Nitrous oxides 
:- N2O5 added to the atmosphere by organic matters and fertilizers.
* Effects
:- Melting of glaciers and polar ice caps, a rise in sea level, increase in growth of parasites and pestes, increase in precipitation and decrease in soil moisture content.
* Prevention
:- By using energy efficient devices in automobiles, by minimizing the use of fossils fuels.

:- By using recyclable & reusable products.
:- By reusing home wastes, newsprints, cardboard etc.
:- By planting more and more trees.